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标题：Dynamic interfacial properties of human apolipoproteins A-IV and B-17 at the air/water and oil/water interface
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作者：Richard B. Weinberg ; Victoria R. Cook ; Jeanine A. DeLozier 等
期刊名称：JLR Papers In Press
印刷版ISSN：0022-2275
电子版ISSN：1539-7262
出版年度：2000
卷号：41
期号：9
页码：1419-1427
语种：English
出版社：American Society for Biochemistry and Molecular Biology
摘要：Viscoelastic behavior of proteins at interfaces is a critical determinant of their ability to stabilize emulsions. We therefore used air bubble surfactometry and drop volume tensiometry to examine the dynamic interfacial properties of two plasma apolipoproteins involved in chylomicron assembly: apolipoprotein A-IV and apolipoprotein B-17, a recombinant, truncated apolipoprotein B. At the air/water interface apolipoproteins A-IV and B-17 displayed wide area-tension loops with positive phase angles indicative of viscoelastic behavior, and suggesting that they undergo rate-dependent changes in surface conformation in response to changes in interfacial area. At the triolein/water interface apolipoprotein A-IV displayed maximal surface activity only at long interface ages, with an adsorption rate constant of 1.0 × 10⁻³ sec⁻¹, whereas apolipoprotein B-17 lowered interfacial tension even at the shortest interface ages, with an adsorption rate constant of 9.3 × 10⁻³ sec⁻¹. Apolipoprotein A-IV displayed an expanded conformation at the air/water interface and a biphasic compression isotherm, suggesting that its hydrophilic amphipathic helices move in and out of the interface in response to changes in surface pressure. We conclude that apolipoproteins A-IV and B-17 display a combination of interfacial activity and elasticity particularly suited to stabilizing the surface of expanding triglyceride-rich particles. —Weinberg, R. B., V. R. Cook, J. A. DeLozier, and G. S. Shelness. Dynamic interfacial properties of human apolipoproteins A-IV and B-17 at the air/water and oil/water interface. J. Lipid Res. 2000. 41: 1419–1427.
关键词：surface tension ; interfacial elasticity ; drop volume tensiometry ; chylomicron assembly ; cholesterol ; monolayers ; triglyceride-rich particles